1b.Approach (from AD-416):
M. rotundata and O. lignaria will be exposed to low-temperature storage for varying durations after which flight metabolism and critical pO2 values will be determined and compared against control values. The following developmental stages will be examined during this investigation; eye pigmented pupae and ready-to-emerge adults of M. rotundata and the overwintering stages of both M. rotundata and O. lignaria. If flight metabolism or critical pO2 values are significantly different from the controls they will be incorporated into the post-storage screening of stored bees to measure their post-storage quality. The components of low-temperature protocol, such as the base storage temperature, the temperature of the high-temperature pulse, the pulse duration and frequency and atmospheric gas mixture will be optimized to improve post-storage availability and quality of the bees.

3.Progress Report:

The object of this cooperative research project is to improve the husbandry of M. rotundata and O. lignaria by; (1) isolating and characterizing sublethal wounding induced by low-temperature storage; (2) develop quality control biomarkers based on the characterized sublethal wounds to improve storage protocols thereby increasing the availability and quality of these pollinators.

In this reporting period we conducted two major experiments. In the first, postdiapausing M. rotundata were exposed to long-term low-temperature storage (6°C) in which the bees received a daily high-temperature pulse (fluctuating thermal regime, FTR) after which body mass, flight metabolism and critical pO2 values were determined and compared against control values. No significant differences were found between the FTR treated bees and the controls demonstrating that the storage duration of M. rotundata can be doubled without an observable sublethal affects. In the second experiment, developing pupae of M. rotundata were exposed for 2 weeks under an FTR storage regime and adult longevity was measured. Bees stored under FTR lived significantly longer then either the nonstored or 6°C control bees. These results demonstrate that interrupting development with a short FTR treatment can increase adult lifespan and this should lead to an increase number of flowers pollinated and the number brood produced.